A Mole of Atoms:
1 mole is a set number representing 6.022 x 10^23. What an odd number to use for counting isn't it? Why not just use 6 x 10^23? Well 1 mole was a number that represents much more then just a random arbitrary number marking to make counting easier, its actually based on how many atoms are present in 12 grams of carbon-12 which has an atomic weight of 12. This way we can easily weight a sample of a pure element in grams and by comparison analysis we can figure out roughly how many atoms of an element we have!
Follow the links to the side for more information on what a mole is.http://en.wikipedia.org/wiki/Mole_(unit)